JPWO2006101195A1 - Novel microorganism and method for treating green coffee beans using the microorganism - Google Patents

Abstract

New microorganisms that can be fermented without any particular restrictions on fermentation conditions, and that do not incur an increase in raw material costs, and that do not require new processing steps. Provided is a method for treating green coffee beans that imparts a high flavor. A method for treating green coffee beans comprising a fermentation process in which microorganisms are brought into contact with an assimilation component in the presence of green coffee beans and fermented, wherein the microorganism used in the fermentation process is of the genus Geotrichum Of green coffee beans, which are microorganisms belonging to the above.

Description

  The present invention relates to a method for treating green coffee beans, which includes a fermentation process in which microorganisms are brought into contact with an assimilation component in the presence of green coffee beans.

At present, as the demand for coffee beverages increases as preference beverages, consumers' preferences for coffee flavor are also diversified.
In order to meet the needs of such consumers, as a method of creating various coffee flavors, as a commonly practiced method, various roasted coffee beans (light roast to Italian roast) with different degrees of roasting are used. Although the method of making is mentioned, the method of making a microorganism carry out a fermentation process and providing a coffee flavor is disclosed until now (refer patent document 1).
In the method described in Patent Document 1, gonococcus (genus Aspergillus) is used as a microorganism. More specifically, the coffee raw beans that have been crushed and fermented by inoculating koji mold with aspergillus are roasted and the generated coffee flavor components are extracted. Next, the extracted coffee flavor component is added to a coffee product such as a coffee extract, roasted coffee beans, and powdered coffee to enhance the coffee flavor.
Japanese Patent Laid-Open No. 1-112950

  However, in the method using the koji mold of Patent Document 1 described above, as described in the specification, when fermentation is performed using koji mold, it is necessary to limit the fermentation conditions to some extent. For example, since it is difficult to proceed with normal size coffee beans, the coffee beans need to be pulverized and made fine (increase the contact area with koji molds) in order to increase the fermentation rate. Fermentation) The gonococcus must be cultivated at a pH of 3.0-6.5.

  Moreover, this conventional method requires a new processing step of extracting the generated coffee flavor component and adding the extracted liquid to the above-described coffee product in addition to the normal coffee beverage production step. As a result, it takes time and labor, and requires raw coffee beans (pulverized) for inoculating and fermenting the koji mold separately, resulting in high raw material costs. This conventional method is a method for enhancing the coffee flavor, and does not disclose a method for creating a new coffee flavor.

  The present invention has been made in view of the above circumstances, and is capable of performing a novel microorganism that can be fermented without particularly restricting the fermentation conditions. The present invention provides a method for treating green coffee beans using the above-mentioned novel microorganism, which can provide a new high-quality flavor to a coffee beverage by a simple operation without requiring a process.

(Configuration 1)
A first characteristic configuration of the present invention is a method for treating green coffee beans, which includes a fermentation process in which microorganisms are brought into contact with an assimilated component in the presence of green coffee beans and fermented, and is used in the fermentation process. Is a method for treating green coffee beans, which are microorganisms belonging to the genus Geotrichum.

(Configuration 2)
According to a second characteristic configuration of the present invention, the microorganism belonging to the genus Geotrichum is selected from the group consisting of Geotricum candidum, Geotrichum rectangulatum, and Geotricum crebanium. It is in.

(Configuration 3)
According to a third characteristic configuration of the present invention, the microorganism belonging to the genus Geotrichum is a new strain of Geotrichum sp. Having an international deposit number of FERM BP-10300 or a mutant thereof, or a transformant thereof. In that point.

(Configuration 4)
A fourth characteristic configuration of the present invention is that the fermentation process is a process in which microorganisms are fermented in the presence of coffee fruit.

(Configuration 5)
A fifth characteristic configuration of the present invention is that the coffee fruit is directly brought into contact with microorganisms for fermentation treatment.

(Configuration 6)
The 6th characteristic structure of this invention exists in the point which is the coffee beans obtained by the processing method as described in any one of Claims 1-5.

(Configuration 7)
A seventh characteristic configuration of the present invention is roasted coffee beans obtained by roasting green coffee beans as defined in claim 6.

(Configuration 8)
The eighth characteristic configuration of the present invention is a coffee beverage obtained by using the roasted coffee beans as claimed in claim 7 as a raw material.

(Configuration 9)
The ninth feature of the present invention is that it is a new strain of Geotricum sp. Having an international deposit number of FERM BP-10300, a variant thereof, or a transformant thereof.

According to the method for processing green coffee beans described in the first characteristic configuration of the present invention, a new flavor component can be easily imparted to green coffee beans by a simple operation.
Raw coffee beans have the property of absorbing water in preparation for germination, and certain microorganisms such as yeasts decompose (ferment) organic compounds (assimilation components) to produce alcohols, organic acids, esters. It is known that it can produce | generate a kind etc. (henceforth a fermentation component).
Therefore, when fermentation processing is performed by bringing microorganisms into contact with the assimilation component in the presence of green coffee beans, the produced fermentation components can be absorbed into the green coffee beans together with moisture. As a result, by roasting the coffee beans thus obtained, in addition to the conventional coffee flavor components generated in the roasting process, new flavor components (fermented components) generated by fermentation As a result, a new flavor can be imparted to the coffee beverage extracted from the roasted coffee beans.

  Furthermore, as a feature of the present invention, a microorganism belonging to the genus Geotrichum is used in the fermentation step. Unlike the case of using Aspergillus (Aspergillus genus) in the prior art, this microorganism does not need to grind green coffee beans when fermented, and normal green coffee beans can be used. In addition, there are no particular restrictions on the fermentation (culture) conditions (such as the pH and temperature of the culture solution), and normal and relatively simple fermentation conditions (for example, coffee fruits (raw coffee beans and pulp (utilized components)) And the microorganism is added to a fermenter containing water and mixed and fermented at 20 ° C. to 30 ° C.). Therefore, according to this invention, a new flavor component can be easily provided to green coffee beans by a simple operation.

  As in the method for processing green coffee beans according to the second characteristic configuration of the present invention, Geotricum candidum, Geotricum rectangulatum, or Getrichum When used and fermented, it is possible to impart a new flavor component (fermented component) to green coffee beans, regardless of which microorganism is used, especially coffee obtained using the above microorganisms By using raw beans as raw materials, it has a gorgeous and rich esthetic scent that is balanced with the conventional coffee flavor produced in the roasting process (with reduced alcohol odor) and has a body feeling. Give a taste it is possible to obtain the roasted coffee beans (or coffee drink).

  The microorganism having the international deposit number FERM BP-10300 in the method for processing green coffee beans according to the third characteristic configuration of the present invention is a new strain of Geotrichum sp. Isolated from coffee fruit by the present inventors. It is. By using the new strain, a fresh flavor component (fermentation component) is imparted to the green coffee beans, and roasted coffee beans (or coffee beverages) having a more gorgeous and rich esthetic flavor can be obtained. In the present invention, new strains or mutants thereof, or transformants thereof can be appropriately used. For example, mutants may be spontaneous mutations or artificially induced mutations (treatment with radiation or mutagen), and transformants may include foreign strains in new strains or mutants. It is possible to isolate and use a strain having a more excellent fermentability (or having a feature such as easy handling) from those introduced with.

The coffee fruit in the method for processing green coffee beans according to the fourth characteristic configuration of the present invention refers to the fruit of the Rubiaceae plant called coffee tree, and its structure is roughly the innermost green coffee beans. And the coffee pulp around it, and the outer skin covering the coffee pulp.
In the present invention, since the coffee pulp (part containing sugar and other nutrients) mainly contained in the coffee fruit is used as the assimilation component, it is not necessary to prepare a foreign assimilation component and the raw material cost increases. There is no fear of doing it.
Furthermore, since the present invention can be carried out during a purification process for separating and recovering coffee beans from coffee fruits, unlike the prior art, there is no need to provide a new process for extracting and adding coffee flavor components. A new flavor can be easily imparted to the green coffee beans.

  In the method for processing green coffee beans according to the fifth characteristic configuration of the present invention, coffee is used in the immediate vicinity by using a method (direct method) in which microorganisms are brought into direct contact with the coffee fruit (assistant component) in the fermentation process. Since green beans are present, fermentation components such as alcohols and esters generated by fermentation can quickly migrate into green coffee beans.

  The green coffee beans described in the sixth characteristic configuration of the present invention include a new flavor component (fermented component) produced by fermentation of a microorganism belonging to the genus Geotrichum.

  The roasted coffee bean according to the seventh feature of the present invention has a new flavor produced by fermentation of microorganisms belonging to the genus Geotrichum, in addition to the conventional coffee flavor components produced in the roasting process. Contains ingredients (fermentation ingredients).

  The coffee beverage according to the eighth characteristic configuration of the present invention has a quality derived from a new flavor component (fermented component) generated by fermentation of microorganisms belonging to the genus Geotrichum in addition to the conventional coffee flavor component. It is a tasteful coffee drink with a body sensation with a high aroma (a gorgeous and rich esthetic scent that is balanced with the conventional coffee flavor produced in the roasting process).

  The microorganism having the international deposit number FERM BP-10300 described in the ninth characteristic configuration of the present invention is a new strain of Geotrichum sp. Isolated from coffee fruit by the present inventors. The new strain of the present invention can impart a new flavor component (fermented component) to green coffee beans by bringing it into contact with an appropriate assimilation component and fermenting in the presence of green coffee beans. In addition, this invention includes a new strain or its variant, or those transformants. The mutant of the present invention may be, for example, a natural mutant strain, or can be obtained by artificially inducing a mutation (treatment with radiation or a mutant substance). Moreover, a transformant can be obtained by introducing an expression vector incorporating a foreign gene into the new strain or a mutant thereof according to a standard method.

Embodiments of the present invention will be described below.
Embodiment
(Microorganism)
The microorganism that can be used in the present invention is a microorganism belonging to the genus Geotrichum, preferably Geotricum candidum, Geotricum rectangulatum, or Geotricum cleibum. , A new strain (SAM2421) of Geotrichum sp. Having international deposit number FERM ABP-10300, or a mutant thereof, or a transformant thereof.

  Isolation sources that can isolate microorganisms belonging to the genus Geotrichum of the present invention include soil, plants, air, fiber, wood, house dust, feed, rivers, silage, foods, fruits, cereals, fertilizers, industrial wastewater. , Compost, excrement, gastrointestinal tract and the like, and fruit (coffee fruit) is preferable.

  As an isolation method, for example, the coffee fruit is stirred in sterilized water, the supernatant is smeared on an agar medium containing an appropriate antibiotic and cultured, and the generated colonies are isolated. Although it is mentioned, it is also possible to purchase directly from an appropriate cell storage facility.

  The mutants referred to in the present invention include those obtained by spontaneous mutation or those obtained by artificially inducing mutation (treatment with radiation, mutant substances, etc.), and the DNA base sequence is This refers to an altered strain compared to a wild-type strain (a new strain (SAM2421) of Geotricum sp. Having international deposit number FERM BP-10300).

(1) Spontaneous mutation
Mutations that occur when microorganisms are growing normally under normal circumstances are called spontaneous mutations. The main causes of spontaneous mutations are thought to be errors during DNA replication and endogenous mutagens (nucleotide analogs) (Maki, “Natural Mutations and Repair Mechanisms”, Cell Engineering Vol. 13 No. 8, pp. 663-672, 1994).

(2) Artificial mutation 2-1. Treatment with radiation or mutagens Radiation treatment such as ultraviolet rays or X-rays, or treatment with artificial mutagens such as alkylating agents, damages DNA. The damage is fixed to the mutation during the process of DNA replication.

2-2. Use of PCR (polymerase chain reaction) method Since PCR amplifies DNA in a test tube, a part of intracellular mutation suppression mechanism is lacking, and mutation can be induced at a high frequency. Further, by combining with gene shuffling method (Stemmer, “Rapid evolution of protein in vitro DNA shuffling”, Nature Vol. 370, pp. 389-391, Aug. 1994), avoid accumulation of harmful mutations. Multiple beneficial mutations can be accumulated in a gene.

2-3. Use of mutators In almost all organisms, the mutation suppression mechanism keeps the rate of spontaneous mutations at a very low level. This mutation suppression mechanism has multiple stages involving more than 10 genes. Individuals in which one or more of these genes are disrupted are referred to as mutators because they frequently mutate. These genes are also called mutator genes (Maki, “Spontaneous Mutation and Repair Mechanism”, Cell Engineering Vol. 13 No. 8, pp. 663-672, 1994; Horst et. Al., “Escherichia coli mutator genes”, Trends in Microbiology Vol. 7 No. 1, pp. 29-36, Jan. 1999).

  In addition, the transformant referred to in the present invention refers to a foreign gene possessed by another species of organism as a new strain of the present invention (a new strain of Geotrichum sp. Having international deposit number FERM BP-10300) or a mutation thereof. It means something that is artificially introduced into the body and expressed. As the production method, for example, a foreign gene is incorporated into an appropriate expression vector, and the expression vector is introduced by a known method such as electroporation, calcium phosphate method, liposome method, DEAE dextran method.

  In the present invention, various flavors can be added by selecting the type of microorganism belonging to the genus Geotrichum and fermentation conditions. Therefore, a microorganism strain to which a desirable flavor can be added can be appropriately selected and used.

  The amount of the microorganism used in the present invention is not particularly limited as long as the effect of adding flavor is obtained, but can be appropriately set in consideration of the culture time and cost. For example, a wet weight of about 1 to 100 mg per 100 g of green coffee beans is appropriate.

(Coffee berries)
The coffee fruit in the present invention means the fruit of coffee tree, and its structure is generally composed of raw coffee beans (seed), pulp (part containing sugar and other nutrients), and hull. More specifically, green coffee beans are present on the innermost side, and the surroundings are sequentially covered with silver skin (silver skin), inner skin (parchment), pulp, and outer skin. As the varieties, Arabica, Robusta, Reberica, etc. can be applied, and Brazil, Ethiopia, Vietnam, Guatemala, etc. are applicable as production areas, but there are no particular restrictions. Absent. In addition, the coffee fruit that can be used in this embodiment includes those in an undried and dried state, and the weight ratio when the raw coffee beans are 1 is “coffee berries (undried): Dry coffee fruit: green coffee beans = 6: 4: 1 ”.

(Assimilation component)
Examples of the assimilation component used in the fermentation process of the present invention include fruit pulp, fruit juice, sugar, medium, etc., preferably coffee pulp. However, the coffee pulp in the present invention means, for convenience, all parts of the coffee fruit (whether undried or dried) other than the green coffee beans and the outer skin.

  Coffee pulp may be used in the state of coffee fruit that has not undergone a refining process, or it can be used in the state of pulp obtained when separated from green coffee beans in the refining process. . The coffee pulp may be undried or dried. In addition, it is possible to use other pulps such as grape pulp, cherries pulp, peach pulp, etc. as needed, and these pulps including coffee pulp can be used alone or arbitrarily. You may use it in combination.

  Assimilation components other than the above-described pulp are fruit juice (eg, grapes, peaches, apples, etc.), sugars (eg, monosaccharides, disaccharides, polysaccharides, etc. taken from plants such as sugarcane and sweet potatoes), grains (eg, Wort obtained by saccharification of malt), medium, and the like, but are not particularly limited as long as the microorganism can assimilate, and these assimilation components including pulp are used alone or in any combination. May be used.

(How to expose coffee pulp)
When using the coffee fruit as it is and using the coffee pulp in it as an assimilation component, a method of exposing the coffee pulp to at least a part of the coffee fruit surface may be used in order to increase the fermentation rate.

  As a method of exposing the coffee pulp, the harvested coffee fruit may be scratched with a sharp blade or the like, or the threshing device may be used to apply pressure to the coffee fruit so that the outer skin is cut. Good, but do not damage the coffee beans inside. Alternatively, a peeler or the like may be used to peel only the outer skin of the coffee fruit to expose the pulp. In addition, when the coffee fruit is harvested, it is not necessary to perform the above-described pulp exposing operation for those that are accidentally scratched and at least a part of the pulp is exposed. Moreover, also when using the coffee pulp obtained when it isolate | separates from a green coffee bean in a refinement | purification process, it is not necessary to perform especially the exposure operation of the above-mentioned fruit meat, and it ferments by adding a green coffee bean separately.

(Fermentation process)
1. In the present invention, for example, the following method may be mentioned as a method for bringing a microorganism into contact with an assimilation component in the fermentation step.
(A) Direct method The direct method is a method in which microorganisms are brought into direct contact with the assimilation component in the presence of green coffee beans. For example, by spraying or spraying microorganisms on coffee fruit (or a mixture of coffee pulp and green coffee beans obtained when separated from green coffee beans in the refining process) with at least partly exposed coffee pulp Fermented by direct contact. In particular, when fermenting with coffee fruits that have exposed some pulp, the sugars to be assimilated are localized at high concentrations in the pulp so that fermentation proceeds efficiently and green coffee beans are present in the immediate vicinity. Therefore, fermentation components such as alcohols and esters generated by fermentation can quickly migrate into green coffee beans. In addition, when using the dried coffee fruit (or coffee pulp), you may ferment in the state which included water | moisture content moderately. For microorganisms belonging to the genus Geotricum, the direct method can be suitably used.

(B) Indirect method The indirect method prepares a fermenter equipped with a fermented liquid, adds green coffee beans, assimilated components, and microorganisms to the fermented liquid, and converts microorganisms into assimilated components that can be eluted in the fermented liquid. It is a method of contacting. For example, microorganisms and coffee fruit (or a mixture of coffee pulp and green coffee beans obtained when separated from green coffee beans in the refining process) in which the coffee pulp is at least partially exposed in the fermentation liquid. Add and ferment.

2. Fermentation conditions The conditions for fermentation of microorganisms are not particularly limited as long as fermentation can be carried out. Conditions suitable for fermentation (for example, the type of microorganism to be used and the amount of bacteria (initial number of bacteria), The type and amount (concentration), temperature, humidity, pH, oxygen or carbon dioxide concentration, fermentation time, etc.) of the assimilation component can be appropriately set. In addition, for example, in addition to the above assimilation component, an additive such as a pH adjuster, a commercially available nutrient medium for supplementing a nitrogen source or a carbon source, and the like can be supplementarily added as necessary. .

  In particular, in the fermentation process of the present invention, in order to prevent the propagation of other microorganisms (miscellaneous bacteria), the conditions such as temperature, pH and carbon dioxide concentration may be controlled for fermentation. For example, fermentation is performed in a low-temperature environment that can suppress the propagation of other bacteria such as 15 to 30 ° C., and a pH adjuster or the like (citric acid, malic acid, lactic acid, etc.) is added as necessary, More anaerobic (or aerobic) in which fermentation can be performed under pH conditions that can suppress the growth of other bacteria, or the growth of other bacteria can be suppressed by increasing the carbon dioxide concentration (or oxygen concentration). Fermentation may be carried out under mild conditions.

  In the fermentation process of the present invention, the above fermentation conditions (for example, the type of microorganism to be used and its amount (initial number of bacteria), the type and amount (concentration) of the assimilation component, temperature, humidity, pH, oxygen Alternatively, the fermentation process can be carried out in a thermostatic bath, tank, or storage where the carbon dioxide concentration, fermentation time, etc.) can be controlled automatically and / or manually.

  The time required for the fermentation process is not limited, and may be appropriately selected depending on the quality and strength of the added flavor, or depending on the microorganism and the assimilating component. Moreover, you may complete | finish a fermentation process on the basis of exhaustion of an utilization component.

  When ending the fermentation process, methods such as heat sterilization, water washing, sun drying, separation of assimilated components and green coffee beans, or roasting can be combined. For example, when using a dryer, fermentation can be terminated by drying at 50 to 60 ° C. for about 1 to 3 days.

3. An example of a fermentation process Here, the example which ferments using a coffee fruit is demonstrated.
First, the microorganism is pre-cultured to prepare a suspension thereof. Specifically, the microorganism is aerated in an appropriate liquid medium, and after culturing, the culture solution is centrifuged to remove the supernatant, and the resulting pellet (microorganism mass) is suspended in sterilized water.
Using the suspension, for example, a fermentation process can be performed during the purification process of green coffee beans.
There are two known refining processes for obtaining green coffee beans from non-water-washing and water-washing.
The non-washing type is a method of harvesting coffee berries and then drying them as they are to thresh to remove husks, pulp, inner skins, silver skins, etc. to obtain green coffee beans.
After washing the coffee berries, they are submerged in a water tank to remove impurities, and after removing the outer skin and pulp with a pulp remover, submerged in water to dissolve and remove the sticky material, and then washed with water. In this method, the dried product is threshed to remove the inner skin and the silver skin to obtain green coffee beans.
Non-washing purification processes are easy to operate, but are mainly applied in areas where the climate is dry. On the other hand, the washing-type refining process is mainly applied in rainy areas.

  First, in the non-washing purification process, for example, coffee berries are harvested, the surface of the coffee pulp is exposed using a knife or the like to partially expose the coffee pulp, and the microbial suspension is sprayed by the above direct method. Then, it is fermented by direct contact with microorganisms and then dried.

  Further, in the washing type purification process, for example, when the coffee fruit is harvested, the surface of the coffee pulp is exposed by using a knife or the like to partially expose the coffee pulp, and the impurities are removed by submerging in the water tank. The microorganisms (suspension) are added together in a water tank (fermentor) by an indirect method and fermented. Since the pulp is exposed with scratches, sugars and the like (assimilation component) in the pulp are easily eluted in the water tank, and fermentation by microorganisms is promoted. Alternatively, before the harvested coffee berries are submerged in the aquarium, or before the coffee berries are submerged in the aquarium to remove impurities and removed from the aquarium, the coffee pulp is removed by the direct method or the indirect method described above. You may make it implement fermentation.

  The present invention may also be fermented by the above-mentioned direct method by exposing the pulp while growing on the tree before the coffee fruit is harvested.

  After the fermentation process, the coffee berries are washed away with microorganisms with water, etc., or separated, or the microorganisms are left attached and the pulp is removed and threshed according to the normal refining process. Are separated (one or two green coffee beans are collected from one coffee fruit).

  The green coffee beans thus separated can be roasted by an ordinary method, and various roasted coffee beans (light roast to Italian roast) with different degrees of roasting can be obtained.

  The obtained roasted coffee beans can be used for drinking as regular coffee by pulverizing, adding water, filtering and extracting with a filter medium, and instant coffee, coffee extract, canned coffee, etc. as industrial raw materials Is possible.

  EXAMPLES Hereinafter, although an Example demonstrates this invention concretely, this invention is not limited to these.

(Isolation and identification of SAM2421 strain)
SAM2421 strain which can be suitably used in the present invention was isolated by the following method.
Coffee fruit was tested as one of the sources of microbial isolation. Five coffee fruits (from Okinawa) and 5 ml of sterilized water were placed in a test tube and stirred with a vortex mixer. 100 μl of the supernatant was applied to a YM agar medium supplemented with 100 ppm of chloramphenicol at two different concentrations as it was diluted 1000-fold. After culturing at 23 ° C. for 4 days, 5 colonies were isolated as a result. These five strains were cultured by aeration at 27 ° C. for 3 days using YM medium or red cocoon concentrate (mast). After removing the supernatant by centrifugation (3000 rpm, 10 min), the above five types of strains were suspended in water to obtain five types of suspensions.

Five Erlenmeyer flasks (5000 ml capacity) were prepared, and 1000 g of coffee fruits and 1000 mL of each of the above suspension suspensions were diluted in each Erlenmeyer flask to 1000 mL by diluting each of the above 5 types of suspensions with water. 1) was added and mixed. Fermentation was carried out for 72 hours in a constant temperature room maintained at 23 ° C.
At the stage where the flavor characteristic of the fermented liquid is exhibited, each fermented coffee fruit is taken out of the fermented liquid, drained, dried for 48 hours in a dryer at 55 ° C., and then the pulp and outer skin are removed. I got green coffee beans. Of the obtained green coffee beans, 100 g was roasted by a deep roast button operation with a home-use fully-automated coffee beans roaster (CRPA-100 Tortoise Co., Ltd.). The roasting time was about 25 minutes.
As a result of sensory evaluation of the obtained five types of roasted beans and an extract using the same, one of them had a particularly favorable fragrance.

Therefore, for a strain having a particularly preferred flavor, the National Center for Biotechnology Information (NCBI http://www.ncbi.nlm.nih.gov) is a gene database of the partial base sequence of the 18S rDNA gene (ITS4 region and ITS5 region). ) As a result of BLAST homology search on the above, the homology with Galactomyces geotricum registered in the database is 97%, and Geotrichum candidum The homology of was 96%. In addition, the base sequences of the sequenced ITS4 region and ITS5 region are shown in SEQ ID NO: 1 and SEQ ID NO: 2 in the following sequence listing, respectively.
Moreover, the result observed about the property of this strain is shown below.
(1) Settlement: white, the back side is colorless, no pigmentation.
(2) Odor: Strong fermentation odor, sweet and sour odor.
(3) Mycelia: partition walls, colorless, and conidia segmented as the mycelium develops. The child was not confirmed.

  Galactomyces is a full generation name and is classified as a baby fungus. About the said isolate | separated strain | stump | stock isolate | separated this time, although the mycelium was grown on the slide glass and it tried to observe a pupa, it was judged that it was a strain which belongs to the genus Geotrichum (Geotrichum).

  From the above, the isolated strain was identified as a microorganism belonging to the genus Geotrichum that is classified as an incomplete fungus, and was designated as Geotrichum sp. Deposited internationally at the deposit center (deposit number: FERM BP-10300).

  Using various strains (incomplete fungi) of the genus Geotricum to which SAM2421 obtained in Example 1 was applied, the influence of the fermentation process on green coffee beans was examined. The following four strains were used for the experiment.

(1) A new isolate (SAM2421) of Geotricum sp.
(2) Geotrichum candidum (IAM12700), which is the same strain as the new strain purchased from Institute for Molecular Biology, University of Tokyo.
(3) Geotricum rectangulatum (JCM1750), which is a related species of Geotrichum candidum.
(4) Geotrichum klebahnii (JCM2171) purchased from RIKEN Microbial System Storage Facility.

  As a control, (5) the wine yeast Lalvin (L2323) purchased from Setty Company, and (6) the wheat germ Aspergillus niger for shochu, which is classified into the same imperfect bacteria as the genus Geotrichum. Aspergillus niger) was used.

  These six strains were aerated for 3 days at 27 ° C. using YM medium or red cocoon concentrate (mast). After removing the supernatant by centrifugation (3000 rpm, 10 min), the above six types of strains were suspended in water to obtain six types of suspensions.

  Six Erlenmeyer flasks (5000 ml capacity) were prepared, and 1000 g of coffee fruits and 1000 mL of each of the above suspension suspensions were diluted in each Erlenmeyer flask to 1000 mL by diluting each of the above 6 types of suspensions with water. 1) was added and mixed. Fermentation was carried out for 72 hours in a constant temperature room maintained at 23 ° C.

  As fermentation progressed, it began to grow in the form of mycelium on the surface of the fruit suspension, and film formation was observed. At the same time, the fermentation broth had a characteristic flavor.

  After the fermented coffee fruit was taken out from the fermented liquid and drained, it was dried in a dryer at 55 ° C. for 48 hours, and then the skin was removed to obtain six types of green coffee beans. Of the obtained green coffee beans, 100 g was roasted by a deep roast button operation with a home-use fully-automated coffee beans roaster (CRPA-100 Tortoise Co., Ltd.). The roasting time was about 25 minutes.

  Next, sensory evaluation of the six types of roasted beans was performed by five panelists specializing in coffee sensory. 30 g of each roasted bean was put into a special functional glass as it was without crushing, and the glass was covered. At the time of sensuality, the lid was shifted and four types of brewing incense, esthetic incense, roasting incense and alcohol odor were evaluated. Using roasted beans fermented with wine yeast as a control plot, 1 to 5 points were evaluated in increments of 0.1, indicating that larger numbers were stronger and smaller numbers were weak. It was expressed as an average value of five evaluation points (Table 1).

  In the control group using wine yeast, the brewing aroma was strong and a slightly strong alcohol odor was felt, but when each strain of the genus Geotrichum was used, a strange odor such as brewing aroma or alcohol odor was felt. It was found that a light esthetic incense reminiscent of fresh fruit was given. In the case of using closely related Aspergillus, although the intensity of the scent was obtained to some extent, it was a fragrance lacking in gorgeousness and a well-balanced flavor as coffee was not obtained.

(Evaluation of flavor components of roasted beans)
Aroma components were analyzed using gas chromatography (GC). Each of the six types of roasted beans obtained in Example 2 was put into a GC sample tube as it was without being crushed, and the gas in the headspace was measured. In addition to the experimental samples, Brazilian Santos beans (roasted beans) (No. 2) (referred to as Brazilian in the table below) were used. As the apparatus, “Agilent 7694 Headspace Sampler” “Agilent 6890 GC System” was used. The sample was introduced at 60 ° C. for 15 minutes, split 10: 1, and the column used was CP7673wax (length 25 mm × inner diameter 0.25 mm, film thickness 1.2 μm). The temperature was maintained at 40 ° C. for 5 minutes, raised to 220 ° C. at 10 ° C./minute, and held at 220 ° C. for 20 minutes. MSD and FID were used as detectors.

The analysis results of esters and alcohols characteristic of the fermentation treatment process are shown in Table 2 below. Methyl acetate, ethyl acetate, and ethanol are also detected in Brazilian Santos beans (roasted beans), but are significantly detected in wine yeast and samples fermented with various strains of the genus Geotrichum. It was. In the wine yeast sample, as can be seen from the prominence of the above three component amounts, it was found that the alcohol odor was strong, the brewing aroma increased, and the balance was lost.
On the other hand, in samples fermented with various strains of the genus Geotrichum, peaks that are significantly detected in wine yeast and considered to be related to brewing aroma are reduced, and the composition composition is well balanced. I understood. When using closely related Aspergillus, too strong methyl acetate was considered to be one of the causes of poor fragrance balance.

(Sensory evaluation of coffee extract)
A coffee extract was prepared using each of the six types of roasted beans obtained in Example 2 above. Each of the roasted beans was finely ground, and 100 g of hot water was added to 12 g of the pulverized beans and stirred. According to the usual method of cup test, the floated coffee was removed and the supernatant liquid was subjected to sensory evaluation. Conducted by 5 coffee panelists. The evaluation items were five types: fragrance (brewing fragrance, esthetic fragrance, alcohol odor) and taste (bitterness, body feeling). The evaluation results are shown in Table 3 below. As a control group, a fermented liquor of wine yeast was used. The evaluation of the control group was set to 3, and from 1 point to 5 points was evaluated in increments of 0.1, indicating that a larger number was stronger and a smaller number was weak. Expressed as the average value of evaluation points.

(Aroma component of coffee extract)
10 ml of each extract obtained in Example 4 was placed in a GC sample tube and subjected to GC analysis. Other measurement conditions were in accordance with the method of Example 3 described above. The results are shown in Table 4 below.
As in the case of the roasted beans of Example 3 above, in fermentation using wine yeast, it was thought that the amount of volatilization of esters and ethanol was too large, causing a loss of balance and causing an alcohol odor. . However, in the level using Geotricum, the amount was suppressed and the balance was improved. This amount is considered to have created an excellent bean with a rich and rich coffee-like aroma without interfering with fragrance components other than the above.

  As mentioned above, it turned out that a suitable fragrance can be provided by performing fermentation processing of green coffee beans using various bacteria of the genus Geotrichum to which SAM2421 belongs.

The test was carried out using a commercially available Geotrichum strain.
As strains, GEO CA (item number 20000691), GEO CB (item number 20000692), GEO CD1 (item) belonging to Geotricum candidum sold as a starter in cheese manufacture by Christian Hansen No. 200693) and 4 strains of GEO CE (Item No. 20000083) were used. In addition, wine yeast (L2323) was used as a control group.
0.1 g of each of these five strains was weighed and suspended in water, and further diluted with water to 1000 ml. The Erlenmeyer flask (5000 ml volume) was fermented by adding 1000 mL of each of the dilutions and 1000 g of coffee fruit. Fermentation was carried out for 72 hours in a constant temperature room maintained at 23 ° C. As fermentation progressed, it began to grow in the form of mycelium on the surface of the fruit suspension, and film formation was observed. At the same time, the fermentation broth had a characteristic flavor.
After the fermented coffee fruit was taken out from the fermentation broth and drained, it was dried with a dryer at 55 ° C. for 48 hours, and then the peel was removed to obtain five types of green coffee beans. Of the obtained green coffee beans, 100 g was roasted by a deep roasting button operation using a fully automatic home roasting machine (CRPA-100 Tortoise Co., Ltd.). The roasting time was about 25 minutes. Subsequently, sensory evaluation was performed according to the method in Example 2 (Table 5).

In the control group using wine yeast, the brewing aroma was strong and a slightly strong alcohol odor was felt, but when each strain of the genus Geotrichum was used, a strange odor such as brewing aroma or alcohol odor was felt. It was found that a light esthetic incense reminiscent of fresh fruit was given.
Further, a coffee extract was prepared using each of the roasted beans. Each roasted bean was thinned, and 100 g of hot water was added to 12 g of crushed beans and stirred. About the obtained coffee extract, sensory evaluation was performed according to the method of Example 4 (Table 6).

As in the case of the roasted beans, in the control group using wine yeast, the brewing aroma was strong and a slightly strong alcohol odor was felt, but when each strain of the genus Geotrichum was used, the brewing aroma It was found that a light esthetic incense reminiscent of fresh fruit was given, and no off-flavor such as alcohol odor was felt. Moreover, as for the taste, the body sensation was imparted in all cases compared to the control group.
From the above, it was found that a suitable fragrance can be imparted by fermentation of green coffee beans by using various bacteria of the genus Geotrichum.

Using the SAM2421 strain obtained in Example 1, fermentation by a direct method was performed. The SAM2421 strain was subjected to aeration culture at 27 ° C. for 3 days using a red cocoon concentrate (mast). The supernatant was removed by centrifugation (3000 rpm, 10 min), and then the pellet was suspended in water. 1000 g of coffee fruit was put into a 5000 ml flask, sprinkled with 20 ml of the suspension, and stirred well. The flask was covered with aluminum foil and fermented at room temperature (23 ° C. to 30 ° C.) for 3 days. As the fermentation progressed, some fruit juice accumulated at the bottom. On the surface of the fruit, it was observed that the SAM2421 strain was growing white and fluffy, and the inside of the container was filled with a fruity fermented aroma.
After completion of the fermentation, drained water and dried for 48 hours with a 55 ° C. heat dryer, and then the skin was removed to obtain green coffee beans. Of the obtained green coffee beans, 100 g was roasted by a deep roast button operation with a home automatic roasting machine (CRPA-100 Tortoise Co., Ltd.). The roasting time was about 25 minutes.
Next, sensory evaluation of roasted beans was performed by five panelists specializing in sensory coffee. 30 g of roasted beans were put into a special sensory glass as it was without crushing, and the glass was covered. At the time of sensuality, the lid was shifted and four types of brewing incense, esthetic incense, roasting incense and alcohol odor were evaluated. As a control, roasted beans (roasted beans obtained in Example 2) fermented by the indirect method using SAM2421 strain were used. It was shown that a larger number was stronger and a smaller number was weaker, and 1 to 5 points were evaluated in increments of 0.1. It was expressed as the average value of the five evaluation points. Table 7 shows the results.

  Furthermore, a coffee extract was prepared using the roasted beans. The roasted beans were thinned, and 100 g of hot water was added to 12 g of crushed beans and stirred. According to the usual method of cup test, the floated coffee was removed and the supernatant liquid was subjected to sensory evaluation. Conducted by 5 coffee panelists. There were four evaluation items: fragrance (brewing incense, esthetic incense) and taste (bitterness, body feeling). As a control, a coffee extract obtained from roasted beans fermented by the indirect method using SAM2421 strain (the coffee extract obtained in Example 4) was used. As the larger numbers indicate that the smaller numbers are weak, the 1 to 5 points are evaluated in increments of 0.1. The average value of the evaluation points is shown. The results are shown in Table 8.

From the results of Tables 7 and 8, even in comparison with the control group which showed good results in Example 2 and Example 4, it was excellent by the direct method, with aroma more like rich and rich coffee. It turns out that beans can be created.
The obtained roasted beans were analyzed using gas chromatography according to the method of Example 3. As a result, the total peak area of roasted beans by the direct method was 1.6 times that of the control group by the indirect method. When considered together with the sensory evaluation results of the roasted beans and coffee extract described above, it was confirmed that by using the direct method, a high quality flavor can be efficiently imparted without breaking the balance.

  The present invention includes various products (regular coffee, instant coffee, canned coffee, coffee aroma, etc.) from roasted coffee beans processed according to the present invention, including processing of coffee fruit processing such as refining and roasting. It is also very useful in the manufacturing industry of coffee beverages, and can contribute to the further development of such industries.

Claims (9)

A method for treating green coffee beans, comprising a fermentation process in which microorganisms are brought into contact with an assimilated component in the presence of green coffee beans and fermented,
A method for treating green coffee beans, wherein the microorganism used in the fermentation step is a microorganism belonging to the genus Geotrichum.   The microorganism belonging to the genus Geotrichum is from a group of Geotricum klebah, which is selected from the group of Geotrium klebah, which is selected from Geotrium klebah. Processing method.   The coffee according to claim 1, wherein the microorganism belonging to the genus Geotrichum is a new strain of Geotricum sp. Having international deposit number FERM BP-10300, a mutant thereof, or a transformant thereof. Raw beans processing method.   The method for treating green coffee beans according to claim 1, wherein the fermentation step is a step of causing a microorganism to perform a fermentation treatment in the presence of coffee fruit.   The processing method of the green coffee beans of Claim 4 which makes microorganisms contact the said coffee fruit directly, and is fermented.   Green coffee beans obtained by the processing method according to any one of claims 1 to 5.   Roasted coffee beans obtained by roasting green coffee beans according to claim 6.   A coffee beverage obtained by using the roasted coffee beans according to claim 7 as a raw material.   A new strain of Geotrichum sp. Having an international deposit number of FERM BP-10300 or a variant thereof, or a transformant thereof.